JP2014089317A - Display device and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphor display device improved in color reproducibility and contrast.SOLUTION: A display device comprises: an optical shutter element 50 including a plurality of sub-pixels Pr, Pg and Pb; a backlight 60a arranged opposite to the optical shutter element 50; and a phosphor layer 21 which is provided at a side of the optical shutter element 50 opposite to the backlight 60a, and in which a plurality of luminous layers 21r, 21g and 21b are aligned corresponding to the plurality of sub-pixels Pr, Pg and Pb. The display device further comprises, between the optical shutter element 50 and the backlight 60a, an optical filter 70 which has a light directivity for suppressing light obliquely entering a surface of the optical shutter element 50.

Description

  The present invention relates to a display device and an illumination device, and more particularly to a phosphor-type display device that performs color display by performing color conversion with a phosphor and an illumination device used therefor.

  The liquid crystal display device includes, for example, an active matrix drive type liquid crystal display panel in which a plurality of sub-pixels are arranged in a matrix, and a backlight provided on the back side of the liquid crystal display panel. The liquid crystal display device is configured to display an image by adjusting the transmittance of light from the backlight in each sub-pixel of the liquid crystal display panel. Here, the sub-pixel includes, for example, a sub-pixel that performs red display, a sub-pixel that performs green display, and a sub-pixel that performs blue display. The sub-pixel that performs red display adjacent to each other, and the sub-pixel that performs green display , And a sub-pixel that performs blue display, one pixel is formed.

  For example, Patent Document 1 discloses a backlight system having a primary condensing unit that can condense emitted light from a light source such as a three-wavelength cold cathode tube within ± 60 ° with respect to the front direction; By combining with a condensing film that does not have a pattern structure, which is used as a secondary condensing element that has a stronger condensing focus than the primary condensing part, it effectively shields the omission in the oblique direction and unpleasant coloring A condensing system for use in a transmissive liquid crystal display device to be removed is disclosed.

Japanese Patent No. 4103112

  By the way, in a color filter type liquid crystal display device, since most of the light from the backlight is absorbed by the color filter, the light use efficiency is low. A phosphor-type liquid crystal display device that performs display has been proposed.

  The phosphor-type liquid crystal display device includes, for example, an active matrix drive type liquid crystal display panel and a backlight that emits blue light provided on the back side of the liquid crystal display panel. Here, in the active matrix driving type liquid crystal display panel constituting the phosphor type liquid crystal display device, for example, a thin film transistor (hereinafter also referred to as “TFT”) and a pixel electrode are formed in each sub-pixel, Provided between the active matrix substrate and the counter substrate, and the active matrix substrate disposed on the backlight side, the counter substrate provided to face the active matrix substrate, on which the common electrode, the phosphor layer, and the like are formed And a liquid crystal layer.

  The phosphor layer includes a red light emitting layer provided in each subpixel that performs red display, a green light emitting layer provided in each subpixel that performs green display, and a blue light emission provided in each subpixel that performs blue display. With layers. Here, the red light emitting layer contains, for example, a phosphor that emits red light by converting blue light from the backlight into red light. The green light emitting layer contains, for example, a phosphor that emits green light by converting blue light from the backlight into green light. The blue light emitting layer contains, for example, a light scatterer that emits blue light by scattering blue light from a backlight.

  In a phosphor-type liquid crystal display device, when blue light from a backlight is incident on the surface of the phosphor layer from an oblique direction, a light emitting layer other than a predetermined color easily emits light. When emitting light, the blue light from the backlight is incident on the red light emitting layer and the blue light emitting layer adjacent to the light emitting layer, and not only the green light is emitted, but also the red light and the blue light are slightly emitted. The green light cannot be displayed, and when the black display is performed, the red light emitting layer, the green light emitting layer, and the blue light emitting layer emit light slightly, and thus the black display may be brightened. If so, the color reproducibility is lowered or the contrast is lowered, so that the display quality of the phosphor type liquid crystal display device is lowered.

  The present invention has been made in view of this point, and an object of the present invention is to improve color reproducibility and contrast in a phosphor-type display device.

  In order to achieve the above object, according to the present invention, an optical filter having light directivity is provided between an optical shutter element and a backlight.

  Specifically, the display device according to the present invention includes an optical shutter element in which a plurality of sub-pixels are arranged, a backlight provided so as to face the optical shutter element, and opposite to the backlight of the optical shutter element. And a phosphor layer in which a plurality of light emitting layers are arranged so as to correspond to the plurality of sub-pixels, and between the light shutter element and the backlight, the surface of the light shutter element is inclined. An optical filter having a light directivity that suppresses light incident on the light is provided.

  The backlight is provided so as to emit planar blue light from an emission surface on the optical shutter element side, and the phosphor layer converts the blue light from the backlight into red light to convert the red light. A red light emitting layer that emits blue light, a green light emitting layer that emits the green light by converting blue light from the backlight, and a blue light emitted from the backlight by scattering the blue light. A blue light emitting layer may be provided.

  A light shielding layer may be provided between the plurality of light emitting layers arranged in the phosphor layer.

  The optical shutter element and the phosphor layer are integrally provided, and the optical shutter element includes a first substrate provided on the backlight side and the phosphor layer provided so as to face the first substrate. And a liquid crystal layer provided between the first substrate and the second substrate.

  The reflective polarizing plate may be provided between the backlight and the optical filter.

  The illumination device according to the present invention includes a backlight that emits planar light from an emission surface, and light that is provided to face the emission surface of the backlight and suppresses light emitted obliquely from the filter surface. And an optical filter having directivity.

  According to the present invention, since the optical filter having light directivity is provided between the optical shutter element and the backlight, color reproducibility and contrast can be improved in the phosphor type display device.

1 is a cross-sectional view of a display device according to Embodiment 1. FIG. 1 is a cross-sectional view of a lighting device that constitutes a display device according to Embodiment 1. FIG. FIG. 6 is an explanatory diagram for improving color reproducibility in the display device according to the first embodiment. FIG. 6 is an explanatory diagram of contrast improvement in the display device according to the first embodiment. 3 is a graph showing the light directivity of the illumination device that constitutes the display device according to the first embodiment. It is sectional drawing of the illuminating device which comprises the display apparatus which concerns on Embodiment 2. FIG. It is sectional drawing of the illuminating device which comprises the display apparatus which concerns on Embodiment 3. FIG. It is sectional drawing of the illuminating device which comprises the display apparatus which concerns on Embodiment 4. FIG. 10 is a perspective view illustrating a relationship between an arrangement direction of subpixels and an arrangement direction of a prism sheet in a display device according to a fourth embodiment. It is sectional drawing of the illuminating device which comprises the display apparatus which concerns on Embodiment 5. FIG. It is sectional drawing of the illuminating device which comprises the display apparatus which concerns on Embodiment 6.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments.

Embodiment 1 of the Invention
1 to 5 show Embodiment 1 of a display device and a lighting device according to the present invention. Here, FIG. 1 is a cross-sectional view of the liquid crystal display device 90 of the present embodiment. FIG. 2 is a cross-sectional view of the illuminating device 80a constituting the liquid crystal display device 90. FIG. 3 is an explanatory diagram for improving color reproducibility in the liquid crystal display device 90. FIG. 4 is an explanatory diagram for improving contrast in the liquid crystal display device 90.

  As shown in FIG. 1, the liquid crystal display device 90 includes a liquid crystal display panel 50 provided as an optical shutter element, a backlight 60a provided opposite to the liquid crystal display panel 50, and the liquid crystal display panel 50 and the backlight 60a. And an optical filter 70 provided therebetween. Here, as shown in FIG. 1, the illumination device 80 a includes a backlight 60 a and an optical filter 70.

  In the liquid crystal display panel 50, as shown in FIG. 1, a plurality of subpixels including a subpixel Pr that performs red display, a subpixel Pg that performs green display, and a subpixel Pb that performs blue display are arranged in a matrix. ing. Further, as shown in FIG. 1, the liquid crystal display panel 50 includes an active matrix substrate 20 provided as a first substrate on the backlight 60 a side and a counter provided as a second substrate so as to face the active matrix substrate 20. The substrate 30, the liquid crystal layer 40 provided between the active matrix substrate 20 and the counter substrate 30, and the active matrix substrate 20 and the counter substrate 30 are bonded together, and the liquid crystal layer is interposed between the active matrix substrate 20 and the counter substrate 30. And a sealing material (not shown) provided in a frame shape so as to enclose 40.

  As shown in FIG. 1, the active matrix substrate 20 includes a transparent substrate 10a such as a glass substrate, a TFT array layer 11 provided on the transparent substrate 10a, and an alignment film 12 provided so as to cover the TFT array layer 11. And. In addition, as shown in FIG. 1, the polarizing plate 13 is affixed on the surface of the transparent substrate 10a on the backlight 60a side.

  The TFT array layer 11 includes, for example, a plurality of gate lines provided on the transparent substrate 10a so as to extend in parallel to each other, a gate insulating film provided so as to cover each gate line, and each gate on the gate insulating film. A plurality of source lines provided so as to extend in parallel to each other in a direction orthogonal to the lines, and a plurality of source lines provided for each intersection of each gate line and each source line, that is, for each sub-pixel which is the minimum unit of an image TFT, an interlayer insulating film provided to cover each TFT, and a plurality of pixel electrodes provided in a matrix on the interlayer insulating film and connected to each TFT. Here, the TFT array layer 11 can be formed by forming the gate line, the gate insulating film, the source line, the TFT, the interlayer insulating film, the pixel electrode, and the like using a known method.

  The alignment film 12 is made of, for example, a polyimide resin (thickness of about 1000 mm) subjected to a rubbing process.

  The polarizing plate 13 is, for example, a pair of a polarizer having light absorption anisotropy obtained by uniaxially stretching a polyvinyl alcohol film on which iodine is adsorbed, a triacetyl cellulose film provided so as to sandwich the polarizer, and the like. And a bonding layer provided on the surface of one of the supports.

  As shown in FIG. 1, the counter substrate 30 includes a transparent substrate 10 b such as a glass substrate, a light shielding layer 21 s provided in a lattice shape on the transparent substrate 10 b (lower side in the figure), and each lattice between the light shielding layers 21 s. A phosphor layer 21 including a red light emitting layer 21r, a green light emitting layer 21g, and a blue light emitting layer 21b, respectively, a planarizing film 22 provided to cover the phosphor layer 21, and a planarizing film 22 So as to cover the common electrode 24, the common electrode 24 provided on the polarizing plate 23, a plurality of photo spacers (not shown) provided in a column shape on the common electrode 24, and the common electrode 24. And an alignment film 25 provided.

  The light shielding layer 21s is made of, for example, a light shielding resin material (thickness of about 5 μm to 20 μm) in which carbon fine particles are dispersed.

  The red light emitting layer 21r is made of, for example, a transparent resin material (thickness of about 5 μm to 20 μm) in which a phosphor that emits red light is converted by converting blue light Lb from the illumination device 80a into red light. Has been.

  The green light emitting layer 21g is made of, for example, a transparent resin material (thickness of about 5 μm to 20 μm) in which a phosphor that emits green light is converted by converting the blue light Lb from the lighting device 80a into green light. Has been.

  The blue light emitting layer 21b is made of, for example, a transparent resin material (thickness of about 5 μm to 20 μm) in which a light scatterer that emits blue light is scattered by scattering the blue light Lb from the lighting device 80a. Yes.

  The planarizing film 22 is made of, for example, a transparent resin material (thickness of about 1 μm to 50 μm) such as an acrylic resin.

  The polarizing plate 23 is, for example, a pair of a polarizer having light absorption anisotropy obtained by uniaxially stretching a polyvinyl alcohol film on which iodine is adsorbed, and a triacetyl cellulose film provided so as to sandwich the polarizer. And a bonding layer provided on the surface of one of the supports.

  The common electrode 24 is made of a transparent conductive film (thickness of about 1000 mm) such as an ITO (indium tin oxide) film formed by sputtering, for example.

  The photo spacer is made of, for example, a phenol novolac photosensitive resin (thickness of about 4 μm) or the like.

  The alignment film 25 is made of, for example, a polyimide resin (thickness of about 1000 mm) subjected to a rubbing process.

  The liquid crystal layer 40 is made of, for example, a nematic liquid crystal material having electro-optical characteristics.

  As shown in FIG. 1, the backlight 60 a includes a light source unit 59 a that emits planar blue light La from the emission surface F, and a reflection unit 51 provided on the lower side of the light source unit 59 a in the drawing. .

  The reflection part 51 is made of, for example, a reflection sheet on which a light-reflective thin film such as a silver film is deposited, a multilayer film reflection sheet in which at least two kinds of thin films having different refractive indexes are alternately stacked, a diffusion reflection plate, and the like. It is configured.

  As shown in FIG. 2, the light source unit 59 a includes a plate-shaped transparent light guide plate 53, a plurality of point light sources 52 provided in a row on the side of the light guide plate 53, and the light guide plate 53 on the upper side in the drawing. The provided diffusion plate 54, the prism sheet 55 provided on the upper side of the diffusion plate 54 in the drawing, the prism sheet 56 provided on the upper side of the prism sheet 55 in the drawing, and the upper side of the prism sheet 56 in the drawing. The diffusion plate 57 is provided.

  The point light source 52 includes, for example, an LED (light emitting diode) or a laser that emits blue light La having a wavelength range of about 400 nm to 500 nm.

  The light guide plate 53 is made of, for example, a transparent resin such as an acrylic resin or a polycarbonate resin.

  The diffusion plates 54 and 57 include, for example, a base film such as polyester and a resin layer provided on the base film and having transparent beads dispersed therein.

  As shown in FIG. 2, the prism sheets 55 and 56 are formed such that a plurality of grooves having an isosceles triangle cross section are adjacent to each other, and the apex angle of a prism formed by a pair of adjacent grooves is about 90 °. A film made of acrylic resin or the like formed in As the prism sheets 55 and 56, for example, a brightness enhancement film of BEF (Brightness Enhancement Film) series manufactured by Sumitomo 3M Limited is preferably used. Here, as shown in FIG. 2, each groove of the prism sheet 55 and each groove of the prism sheet 56 are provided on the diffusion plate 57 side and are provided so as to be orthogonal to each other.

  The optical filter 70 is, for example, a multilayer reflection filter in which a plurality of dielectric films are stacked, and the blue light La from the light source unit 59a repeatedly reflects between the reflection unit 51 as shown in FIG. Thus, the angle at which the blue light La is transmitted and emitted is configured to fall within a predetermined range. That is, the optical filter 70 has a light directivity that suppresses light incident obliquely on the surface of the liquid crystal display panel 50. Specifically, the optical filter 70 includes a transparent substrate such as a glass substrate, a titanium oxide film (refractive index 2.42 for a wavelength of 450 nm, a thickness of about 55 nm) and a silicon oxide film (for a wavelength of 450 nm) provided on the transparent substrate. And a dielectric laminated film in which about 70 layers having a refractive index of 1.47 and a thickness of about 90 nm are alternately laminated. The upper and lower thick broken lines in FIG. 1 of the optical filter 70 indicate the light distribution of the blue light La before entering the optical filter 70 and the light distribution of the blue light Lb after exiting the optical filter 70. ing.

  In the liquid crystal display device 90 having the above-described configuration, a predetermined voltage is applied to the liquid crystal layer 40 disposed between each pixel electrode on the active matrix substrate 20 and the common electrode 24 on the counter substrate 30 at each subpixel Pr, Pg, Pb. By changing the alignment state of the liquid crystal layer 40 when applied, the transmittance from the blue light Lb from the illumination device 80a is adjusted by the subpixels Pr, Pg, Pb, and red light, green through the phosphor layer 21 is adjusted. Light and blue light are appropriately emitted to display an image.

  Specifically, when green display is performed, the blue light Lb from the backlight transmitted and emitted through the optical filter 70 is vertically incident on the surface of the liquid crystal display panel 50 as shown in FIG. In the sub-pixel Pr that performs the blue display and the sub-pixel Pb that performs the blue display, the sub-pixel Pg that is blocked by the polarizing plate 23 based on the alignment state of the liquid crystal layer 40 and that performs the green display is based on the alignment state of the liquid crystal layer 40. By passing through the polarizing plate 23 and reliably entering only the green light emitting layer 21g, only the green light Lg can be emitted as display light.

  When performing black display, the blue light Lb from the backlight transmitted and emitted through the optical filter 70 is vertically incident on the surface of the liquid crystal display panel 50 as shown in FIG. 4 to perform red display. The sub-pixel Pr, the sub-pixel Pg that performs green display, and the sub-pixel Pb that performs blue display, that is, all sub-pixels, are reliably blocked by the polarizing plate 23 based on the alignment state of the liquid crystal layer 40. Light that passes through the panel 50 unnecessarily can be suppressed.

  Next, a specific experiment will be described. Here, FIG. 5 is a graph showing the light directivity of the illumination device 80a. In the graph of FIG. 5, a solid curve a indicates the light directivity of the example, and a broken curve b indicates the light directivity of the comparative example. Further, the relative intensity on the vertical axis of the graph of FIG. 5 is a value where the maximum luminance of the comparative example is 1.

  Specifically, as an example, the illumination device 80a of the present embodiment is prepared, and as a comparative example, an illumination device in which the optical filter 70 of the illumination device 80a of the present embodiment is omitted is prepared, and the emission of each illumination device is prepared. The luminance at the measurement point at the center of the surface was measured while changing the extreme (inclination angle from the normal direction) using a luminance meter capable of moving on an arc including the vertex of the hemisphere centered on the measurement point. Here, a color luminance meter BM5A manufactured by Topcon Techno House Co., Ltd. was used as the luminance meter.

  As an experimental result, as shown in FIG. 5, in the example, light is hardly detected at polar angles of −90 ° to −30 ° and + 30 ° to + 90 °, and light is incident at polar angles of −30 ° to + 30 °. In contrast, in the comparative example, light of about 10% to 30% of the maximum luminance is detected at polar angles of −90 ° to −30 ° and + 30 ° to + 90 °, and the light is widely distributed. It was confirmed. Moreover, in the Example, it was also confirmed that the intensity | strength of 0 degree of polar angles improves about 25% compared with the intensity | strength of the 0 degree polar angle of a comparative example.

  As described above, according to the illumination device 80a of this embodiment and the liquid crystal display device 90 including the same, the liquid crystal display panel 50 in which the plurality of subpixels Pr, Pg, and Pb are arranged and the liquid crystal display panel 50 are provided. An optical filter 70 having a light directivity that suppresses light incident obliquely on the surface of the liquid crystal display panel 50 is provided between the backlight 60a provided so as to face the backlight 60a. The blue light Lb from the backlight 60 a thus easily enters the surface of the liquid crystal display panel 50 perpendicularly. Therefore, it is difficult for the light Lb from the backlight 60a to enter the light emitting layers 21r, 21g, and 21b of the phosphor layer 21 corresponding to the subpixels Pr, Pg, and Pb of the liquid crystal display panel 50 obliquely. Accordingly, when performing color display, only the predetermined light emitting layers 21r, 21g, and 21b corresponding to the predetermined sub-pixels Pr, Pg, and Pb can easily emit light, so that color reproducibility is improved and black color is improved. In the case of performing display, since light that passes through the liquid crystal display panel 50 unnecessarily is suppressed, contrast is improved, and the color reproducibility and contrast can be improved in the phosphor-type liquid crystal display device 90. it can.

  Further, according to the illumination device 80a of this embodiment and the liquid crystal display device 90 including the illumination device 80a, the planar blue light Lb (with a wavelength of about 400 nm to 500 nm) supplied from the backlight 60a to the liquid crystal display panel 50 is ultraviolet light. (The wavelength is less than about 400 nm), it is not necessary to cut light in the ultraviolet region, so that the light use efficiency can be increased compared with the case where white light is used. The planar blue light Lb supplied to the panel 50 has a shorter wavelength than the red light emitted by color conversion by the red light emitting layer 21r and the green light emitted by color conversion by the green light emitting layer 21g. Due to the energy transition of the excitation light, the peak position of the fluorescence emission spectrum becomes longer than the peak position of the excitation light emission spectrum. Cormorants phenomenon can be effectively utilized.

  Further, according to the illumination device 80a of this embodiment and the liquid crystal display device 90 including the illumination device 80a, the light shielding layer 21s is provided between the plurality of light emitting layers 21r, 21g, and 21b arranged in the phosphor layer 21. Therefore, the red light emitting layer 21r, the green light emitting layer 21g, and the blue light emitting layer 21b are separated from each other via the light shielding layer 21s, thereby further suppressing unnecessary light emission between the adjacent subpixels Pr, Pg, Pb. it can.

  In the present embodiment, the liquid crystal display device 90 in which the light shielding layer 21s is provided on the phosphor 21 of the counter substrate 30 is illustrated, but the present invention is a liquid crystal display device in which the light shielding layer is provided on the active matrix substrate side, In addition, the present invention can also be applied to a liquid crystal display device in which a light shielding layer is provided on both the active matrix substrate side and the counter substrate side.

<< Embodiment 2 of the Invention >>
FIG. 6 is a cross-sectional view of the illumination device 80b constituting the liquid crystal display device of the present embodiment. In addition, in each following embodiment, the same code | symbol is attached | subjected about the same part as FIGS. 1-5, and the detailed description is abbreviate | omitted.

  In the first embodiment, the liquid crystal display device 90 including the illumination device 80a in which only the optical filter 70 is provided between the liquid crystal display panel 50 and the backlight 60a is illustrated. However, in the present embodiment, the liquid crystal display panel 50 and A liquid crystal display device including an illumination device 80b in which an optical filter 70 and a reflective polarizing plate 65 are provided between the backlights 60a is illustrated.

  As shown in FIG. 6, the liquid crystal display device of the present embodiment includes a liquid crystal display panel (50, see FIG. 1) provided as an optical shutter element, a backlight 60a provided opposite to the liquid crystal display panel 50, An optical filter 70 provided between the liquid crystal display panel 50 and the backlight 60a and a reflective polarizing plate 65 provided between the backlight 60a and the optical filter 70 are provided. Here, the illuminating device 80b includes a backlight 60a, a reflective polarizing plate 65, and an optical filter 70 as shown in FIG.

  The reflective polarizing plate 65 is configured to transmit, for example, P-polarized light and reflect S-polarized light out of blue light from the backlight 60a. As the reflective polarizing plate 65, for example, a DBEF (Dual Brightness Enhancement Film) series brightness enhancement film manufactured by Sumitomo 3M Limited is preferably used.

  According to the illumination device 80b and the liquid crystal display device including the same according to the present embodiment, the optical filter 70 having light directivity is provided between the liquid crystal display panel 50 and the backlight 60a as in the first embodiment. Therefore, color reproducibility and contrast can be improved in the phosphor type liquid crystal display device.

  Moreover, according to the illuminating device 80b of this embodiment and a liquid crystal display device provided with the same, between the backlight 60a and the optical filter 70, for example, P-polarized light of blue light from the backlight 60a is transmitted. Since the reflective polarizing plate 65 that reflects S-polarized light is provided, the S-polarized light of the blue light of the backlight 60a is reflected by the reflective polarizing plate 65 and reused, so that the light of the backlight 60a is reflected. Utilization efficiency can be improved.

  In this embodiment, the configuration in which the reflective polarizing plate 65 is applied to the liquid crystal display device 90 of the first embodiment is illustrated, but the reflective polarizing plate 65 is applied to the liquid crystal display device of each embodiment described later. Also good.

<< Embodiment 3 of the Invention >>
FIG. 7 is a cross-sectional view of the illumination device 80c constituting the liquid crystal display device of the present embodiment.

  In the first and second embodiments, the liquid crystal display device including the edge light type backlight 60a is illustrated. However, in the present embodiment, the liquid crystal display device including the direct type backlight 60b is illustrated.

  As shown in FIG. 7, the liquid crystal display device of this embodiment includes a liquid crystal display panel (50, see FIG. 1) provided as an optical shutter element, and a backlight 60b provided to face the liquid crystal display panel 50. And an optical filter 70 provided between the liquid crystal display panel 50 and the backlight 60b. Here, as shown in FIG. 1, the illumination device 80 c includes a backlight 60 b and an optical filter 70.

  As shown in FIG. 7, the backlight 60b includes a light source unit 59b that emits planar blue light (La, see FIG. 1) from the emission surface (F, see FIG. 1), and a lower side of the light source unit 59b in the figure. And a reflecting portion 51 provided on the head.

  As shown in FIG. 7, the light source unit 59 b includes a plurality of point light sources 52 arranged above the reflection unit 51 (for example, in a matrix), and diffusion provided on the upper side of each point light source 52 in the drawing. A plate 54, a prism sheet 55 provided on the upper side of the diffusion plate 54 in the drawing, a prism sheet 56 provided on the upper side of the prism sheet 55 in the drawing, and a diffusion plate 57 provided on the upper side of the prism sheet 56 in the drawing. And.

  According to the illumination device 80c of this embodiment and the liquid crystal display device including the same, the optical filter 70 having light directivity is provided between the liquid crystal display panel 50 and the backlight 60b as in the first embodiment. Therefore, color reproducibility and contrast can be improved in the phosphor type liquid crystal display device.

<< Embodiment 4 of the Invention >>
FIG. 8 is a cross-sectional view of an illuminating device 80d constituting the liquid crystal display device of the present embodiment. FIG. 9 is a perspective view showing the relationship between the subpixel arrangement direction and the prism sheet 58a arrangement direction in the liquid crystal display device of the present embodiment.

  In the first to third embodiments, the liquid crystal display device including the illumination devices 80a to 80c provided with the pair of prism sheets 55 and 56 is illustrated. However, in the present embodiment, a single prism sheet 58a is provided. The liquid crystal display device provided with the illuminating device 80d is illustrated.

  As shown in FIG. 8, the liquid crystal display device of this embodiment includes a liquid crystal display panel (50, see FIG. 1) provided as an optical shutter element, and a backlight 60c provided to face the liquid crystal display panel 50. And an optical filter 70 provided between the liquid crystal display panel 50 and the backlight 60c. Here, the illuminating device 80d includes a backlight 60c and an optical filter 70 as shown in FIG.

  As shown in FIG. 8, the backlight 60c includes a light source unit 59c that emits planar blue light (La, see FIG. 1) from the emission surface (F, see FIG. 1), and a lower side of the light source unit 59c in the figure. And a reflecting portion 51 provided on the head.

  As shown in FIG. 8, the light source unit 59 c includes a plate-shaped transparent light guide plate 53 provided above the reflecting unit 51, and a plurality of point light sources 52 provided in a row on the side of the light guide plate 53. The prism sheet 58a provided on the upper side of the light guide plate 53 in the figure, and the diffusion plate 57 provided on the upper side of the prism sheet 58a in the figure.

  As shown in FIG. 8, the prism sheet 58a is formed such that a plurality of grooves having an isosceles triangle cross section are adjacent to each other, and the apex angle of a prism formed by a pair of adjacent grooves is 60 ° to 70 °. It is a film made of acrylic resin or the like formed to a degree. Moreover, as the prism sheet 58a, for example, a prism sheet of the Diamond Art (registered trademark) series manufactured by Mitsubishi Rayon Co., Ltd. is preferably used. Here, each groove | channel of the prism sheet 58a is provided in the light-guide plate 53 side, as shown in FIG. Further, the direction Dp in which each groove of the prism sheet 58a extends is parallel to the direction Dc in which the light emitting layers 21r, 21g, 21b of the same color, that is, the subpixels Pr, Pg, Pb of the same color are arranged as shown in FIG. It has become.

  According to the illumination device 80d of this embodiment and the liquid crystal display device including the same, the optical filter 70 having light directivity is provided between the liquid crystal display panel 50 and the backlight 60c as in the first embodiment. Therefore, color reproducibility and contrast can be improved in the phosphor type liquid crystal display device.

  In addition, according to the illumination device 80d of this embodiment and the liquid crystal display device including the illumination device 80d, only one prism sheet 58a (and the diffusing plate 57) is required, so that the device can be reduced in thickness and weight.

  Further, according to the illumination device 80d of this embodiment and the liquid crystal display device including the illumination device 80d, the direction Dp in which the grooves of the prism sheet 58a extend and the direction Dc in which the subpixels Pr, Pg, Pb of the same color are arranged are parallel. Therefore, the directivity of the light distribution is increased (the half width is narrowed), and the color reproducibility can be further improved.

  In the present embodiment, the configuration in which the prism sheet 58a is applied to the edge-light type backlight is illustrated, but the prism sheet 58a may be applied to a direct-type backlight.

<< Embodiment 5 of the Invention >>
FIG. 10 is a cross-sectional view of the illumination device 80e constituting the liquid crystal display device of the present embodiment.

  In the fourth embodiment, the liquid crystal display device including the illuminating device 80d in which the light guide plate 53 and the prism sheet 58 are provided independently is illustrated. However, in the present embodiment, the light guide plate 53 and the prism layer 58b are provided integrally. A liquid crystal display device including the illumination device 80e is illustrated.

  As shown in FIG. 10, the liquid crystal display device of this embodiment includes a liquid crystal display panel (50, see FIG. 1) provided as an optical shutter element, a backlight 60d provided to face the liquid crystal display panel 50, And an optical filter 70 provided between the liquid crystal display panel 50 and the backlight 60d. Here, the illumination device 80e includes a backlight 60d and an optical filter 70 as shown in FIG.

  As shown in FIG. 10, the backlight 60d includes a light source unit 59d that emits planar blue light (La, see FIG. 1) from the emission surface (F, see FIG. 1), and a lower side of the light source unit 59d in the figure. And a reflecting portion 51 provided on the head.

  As shown in FIG. 10, the light source unit 59 d includes a plate-shaped transparent light guide plate 53 provided above the reflection unit 51, and a plurality of point light sources 52 provided in a row on the side of the light guide plate 53. The prism layer 58b provided on the lower surface of the light guide plate 53 in the drawing, and the diffusion plate 57 provided on the upper side of the light guide plate 53 in the drawing.

  As shown in FIG. 10, the prism layer 58b is formed, for example, such that a plurality of grooves having a trapezoidal cross section are adjacent to each other, and the apex angle of the prism formed by a pair of adjacent grooves is approximately 45 °. It is comprised by the made acrylic resin. Here, the refractive index (for example, about 1.26) of the prism layer 58b is lower than the refractive index (for example, about 1.59) of the light guide plate 53. The prism layer 58b can be formed, for example, by attaching an acrylic resin film to the surface of the light guide plate 53 and then finely processing the surface of the film.

  According to the illumination device 80e of this embodiment and the liquid crystal display device including the same, the optical filter 70 having light directivity is provided between the liquid crystal display panel 50 and the backlight 60d as in the first embodiment. Therefore, color reproducibility and contrast can be improved in the phosphor type liquid crystal display device.

Embodiment 6 of the Invention
FIG. 11 is a cross-sectional view of the illumination device 80f constituting the liquid crystal display device of the present embodiment.

  In the fifth embodiment, the liquid crystal display device including the illumination device 80e in which the prism layer 58b is provided on the light guide plate 53 is illustrated. However, in the present embodiment, the low refractive index layer 58c and the prism layer 58d are provided on the light guide plate 53. The liquid crystal display device provided with the illuminating device 80f provided in order is illustrated.

  As shown in FIG. 11, the liquid crystal display device of the present embodiment includes a liquid crystal display panel (50, see FIG. 1) provided as an optical shutter element, a backlight 60e provided opposite to the liquid crystal display panel 50, And an optical filter 70 provided between the liquid crystal display panel 50 and the backlight 60e. Here, the illumination device 80f includes a backlight 60e and an optical filter 70 as shown in FIG.

  As shown in FIG. 11, the backlight 60e includes a light source unit 59e that emits planar blue light (La, see FIG. 1) from the emission surface (F, see FIG. 1), and a lower side of the light source unit 59e in the figure. And a reflecting portion 51 provided on the head.

  As shown in FIG. 11, the light source unit 59 e includes a plate-like transparent light guide plate 53 provided above the reflection unit 51, and a plurality of point light sources 52 provided in a row on the side of the light guide plate 53. The low refractive index layer 58c provided on the lower surface of the light guide plate 53 in the drawing, the prism layer 58d provided on the lower surface of the low refractive index layer 58c in the drawing, and the upper side of the light guide plate 53 in the drawing. And a diffusing plate 57 provided on the surface.

  The low refractive index layer 58c is made of, for example, an acrylic resin having a refractive index lower than that of the light guide plate 53 and a refractive index of the prism layer 58d described later (for example, about 1.26).

  As shown in FIG. 11, for example, the prism layer 58d is formed such that a plurality of grooves having a trapezoidal cross section are adjacent to each other, and the apex angle of the prism formed by a pair of adjacent grooves is about 45 °. It is comprised by the made acrylic resin. Here, the refractive index (for example, about 1.59) of the prism layer 58d is higher than the refractive index (for example, about 1.26) of the low refractive index layer 58c, and the refractive index (for example, 1.. 59) or less. The prism layer 58d is formed by, for example, attaching a two-layer film made of an acrylic resin whose light guide plate 53 side becomes the low refractive index layer 58c on the surface of the light guide plate 53, and then finely processing the surface of the outer layer film. By doing so, it can be formed.

  According to the illumination device 80f of this embodiment and the liquid crystal display device including the same, the optical filter 70 having light directivity is provided between the liquid crystal display panel 50 and the backlight 60e, as in the first embodiment. Therefore, color reproducibility and contrast can be improved in the phosphor type liquid crystal display device.

  In each of the above embodiments, a liquid crystal display device that performs color display by performing color conversion with a phosphor is exemplified, but the present invention can also be applied to a color filter type display device.

  Further, in each of the above embodiments, the liquid crystal display device that performs color display with three colors of RGB is illustrated, but the present invention performs color display by adding other colors to the three colors of RGB, or other than RGB. The present invention can also be applied to a display device that performs color display with a plurality of colors.

  In each of the above embodiments, a liquid crystal display device including a backlight that emits blue light is illustrated. However, the present invention includes, for example, a backlight that emits ultraviolet light, and includes only a red light emitting layer and a green light emitting layer. In addition, the present invention can also be applied to a display device including a backlight that emits other monochromatic light, such as a display device in which a predetermined phosphor is dispersed in the blue light emitting layer.

  In each of the above embodiments, a liquid crystal display device having a stripe arrangement in which a plurality of subpixels are arranged in a matrix is illustrated, but the present invention can also be applied to a display device such as a delta arrangement or a mosaic arrangement. .

  In each of the above embodiments, a liquid crystal display device including a liquid crystal display panel as an optical shutter element is illustrated. However, the present invention is also applied to a display device including a micro electro mechanical system (MEMS) as an optical shutter element. be able to.

  As described above, since the present invention improves color reproducibility and contrast, it is useful not only for a phosphor type display device but also for a color filter type liquid crystal device.

F emission surface La, Lb Blue light Pr, Pg, Pb Subpixel 20 Active matrix substrate (first substrate)
21 phosphor layer 21b blue light emitting layer 21g green light emitting layer 21r red light emitting layer 21s light shielding layer 30 counter substrate (second substrate)
40 Liquid crystal layer 50 Liquid crystal display panel (optical shutter element)
60a-60e Backlight 65 Reflective polarizing plate 70 Optical filters 80a-80f Illuminating device 90 Liquid crystal display device

Claims (6)

An optical shutter element in which a plurality of sub-pixels are arranged;
A backlight provided to face the optical shutter element;
A phosphor layer provided on the opposite side of the backlight of the optical shutter element and having a plurality of light emitting layers arranged so as to correspond to the plurality of sub-pixels,
A display device, wherein an optical filter having light directivity for suppressing light incident obliquely on the surface of the optical shutter element is provided between the optical shutter element and the backlight. The backlight is provided to emit planar blue light from the exit surface on the optical shutter element side,
The phosphor layer converts the blue light from the backlight into red light and emits the red light, and converts the blue light from the backlight into green light and emits the green light. The display device according to claim 1, further comprising: a green light emitting layer that emits blue light from the backlight, and a blue light emitting layer that emits the blue light.   The display device according to claim 1, wherein a light shielding layer is provided between the plurality of light emitting layers arranged in the phosphor layer. The optical shutter element and the phosphor layer are provided integrally,
The optical shutter element includes a first substrate provided on the backlight side, a second substrate including the phosphor layer provided to face the first substrate, and the first substrate and the second substrate. The display device according to claim 1, further comprising a liquid crystal layer provided between the two.   The display device according to claim 1, wherein the reflective polarizing plate is provided between the backlight and the optical filter. A backlight that emits planar light from the exit surface;
An illuminating device, comprising: an optical filter that is provided so as to face the emission surface of the backlight and that has light directivity that suppresses light emitted obliquely from the filter surface.

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